1. Field of the Invention
The present invention relates to a video system, particularly to a video system which uses a small size cassette for reducing the size and the weight of a video tape recorder and is chiefly intended for use during photography.
2. Description of Prior Arts
A conventional type of video system is shown in FIG. 1. In this drawing, what is shown as element 1 is a video camera, and element 2 is a VTR, while element 3 is a cable. An image photographed by the video camera 1 is converted into an NTSC signal by the camera, which signal then is sent through the cable 3 to the VTR 2. The VTR 2 converts the NTSC signal, at the time of reproduction, into a signal which can be reproduced by a television set by a built in RF conversion system.
This type of VTR used in a portable video system has the function of recording images on a magnetic tape within a magnetic tape cassette and reproducing the image from said tape. NTSC signals from a video camera and NTSC signals from a television broadcasting station are used as an image recording signal. Also, output signals reproduced in this type of video system are VHF signals obtained by a frequency modulation of the NTSC signals to the VHF band, so that they can be reproduced at a home use TV set having no video input terminal using one of the channels of said TV set. Since a VTR having such reproduction function contains a servo-system for reproduction, a power source, a device to convert reproducing signals to NTSC signals, and an RF conversion system to make a frequency modulation for the NTSC signals, problems such as inconvenience in portability and maneuverability with respect to size and the weight, etc. of a VTR itself are unavoidable.
Also, in a conventional video tape recorder, a system has been known such that, after a power source switch is thrown before a recording is started, a recording button or a reproduction button is pressed to take out a tape from a cassette and the tape is wound around a cylindrical tape guide having a rotating head being built in the same (hereinafter called loading), then said loading is stopped by an output of a loading completion detecting switch. Also, when a stop button is pressed upon completion of a recording, the above-mentioned recording or reproduction button is reset. At this time, the separating of the tape from the cylindrical tape guide and housing the same in the cassette (hereinafter called unloading) is carried out. This function is carried out only when an unloading completion detecting switch has not detected an unloading completion and the stop button is pressed.
However, when such complicated arrangement is employed, not only does the mechanism within a video tape recorder become complicated but there will also be many elements not necessary for operating the system, which is detrimental to reducing the size and weight of the system.